Drum brake electronic parking test device

Abstract

The utility model provides a drum brake electronic parking test device, which belongs to the technical field of detection equipment, and comprises a test board, a simulation drum structure and an electronic parking module, the test board is provided with a mounting position, and the mounting position is used for fixing a tested piece; the simulation drum structure is arranged on the test bench, surrounds the radial periphery of the tested piece, and is in contact with a brake shoe of the tested piece; the simulation drum structure is connected with a pressure sensor; the electronic parking module is electrically connected with the tested piece and used for controlling parking braking of the tested piece. The drum brake electronic parking test device provided by the utility model is in direct communication connection with the electronic control unit of the tested piece through the integrated electronic parking module, simulates an electronic parking trigger signal of a real vehicle, and directly detects the contact pressure between the brake shoe and the simulation drum through the pressure sensor. The problems of input and execution of electronic control signals are solved, and the testing device can accurately reproduce the working condition of electronic parking braking.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of detection equipment, more specifically, relate to a drum brake electronic parking testing arrangement. BACKGROUND

[0002] The drum brake assembly is installed in the inside of the brake drum, and is generally composed of a brake cylinder, a self-adjusting mechanism, a brake shoe, an electronic parking unit, etc. During hydraulic braking, brake fluid is transmitted to the master cylinder assembly through the pipeline, and the piston pushes the brake shoe to make it adhere to the brake drum, thereby achieving braking. During electronic parking braking, the driver presses the parking button, and the ECU drives the electronic parking unit to perform clamping action, thereby achieving parking. During hand brake braking, the brake shoe is driven into contact with the brake drum by manually operating the pull rod or handle, thereby achieving parking.

[0003] The parking clamping force of the drum brake directly affects the parking effect. When the parking clamping force is too large, the structure of the drum brake will be damaged, and when the parking clamping force is too small, it will not meet the requirements of parking on flat ground or slope, causing the vehicle to slide down the slope during parking braking, which seriously affects the safety of parking. Therefore, it is necessary to use a testing device to detect the parking clamping force of the drum brake.

[0004] However, the existing testing device is mainly used for detecting the parking clamping force of the hand-operated drum brake, and cannot be applied to the electronic parking brake drum. UTILITY MODEL CONTENTS

[0005] The utility model aims at providing a drum brake electronic parking testing arrangement, and aims at realizing the parking detection of the drum brake controlled by the electronic parking.

[0006] To achieve the above-mentioned purpose, the utility model adopts the technical scheme of providing a drum brake electronic parking testing arrangement, which comprises:

[0007] A test bench having a mounting position for fixing a measured part;

[0008] An analog drum structure is arranged on the test bench and surrounds the radial periphery of the measured part and is in contact with the brake shoe of the measured part. The analog drum structure is connected with a pressure sensor for detecting the pressure applied by the brake shoe to the analog drum structure; and

[0009] An electronic parking module electrically connected with the measured part for controlling the parking braking of the measured part.

[0010] The drum brake electronic parking testing device has the advantages that, compared with the prior art, the drum brake electronic parking testing device, the test table is used for installing the measured member, the simulation drum structure is used for simulating the brake drum, the electronic parking module is electrically connected with the measured member and is used for controlling the parking brake of the measured member; the electronic parking module is integrated, is directly connected with the electronic control unit of the measured member, simulates the electronic parking trigger signal of the real vehicle, and directly detects the contact pressure between the brake shoe and the simulation drum through the pressure sensor, so that the input and execution of the electronic control signal are solved, and the working condition of the electronic parking brake can be accurately reproduced.

[0011] In a possible implementation, the simulation drum structure comprises:

[0012] At least two clamping blocks are distributed at the radial periphery of the measured member and are in contact with the brake shoes of the measured member; and each clamping block is slidably connected with the test table.

[0013] The design of the at least two clamping blocks achieves more accurate, flexible and safe electronic parking brake testing through the sliding connection and the multi-point pressure detection, and is especially suitable for the development and quality control of the drum brake with strict requirements on the clamping force distribution.

[0014] In some embodiments, the simulation drum structure further comprises:

[0015] At least two sliding blocks are connected with the at least two clamping blocks one by one; and the clamping blocks are slidably connected with the test table through the sliding blocks.

[0016] The position of the clamping block can be accurately controlled through the sliding block, different wear states can be simulated, and the adaptive ability of the electronic parking unit can be verified. Moreover, the sliding block can perform periodic reciprocating motion to simulate the durability test of frequent parking release, in cooperation with the programming control of the test table. In addition, each clamping block is connected with one sliding block, and the multiple sliding blocks move independently, so that even if the unilateral brake shoe is stuck, the remaining sliding blocks can still slide normally, avoiding system lock.

[0017] In some embodiments, a fixed support is arranged on the test table, and the fixed support is located at the radial periphery of the mounting position; and the at least two sliding blocks are slidably arranged on the fixed support.

[0018] The fixed support is a core structural member for supporting the movement of the sliding block and the clamping block in the test table, ensures that the sliding block can only move in a radial straight line, avoids the deflection or torsion of the clamping block, and ensures that the pressure detection direction is consistent with the stress direction of the measured shoe. In addition, as the sliding base, the fixed support can bear the reaction force of the brake shoe when the EPB motor is clamped or released quickly, so as to prevent the deformation of the test table from affecting the measurement accuracy.

[0019] In some embodiments, the test bench has a support plane, and a mounting table is arranged on the support plane, and the mounting position is arranged on the mounting table, and the axial direction of the mounting position is perpendicular to the support plane.

[0020] The fixed support is fixedly arranged on the support plane and located at the periphery of the mounting table.

[0021] The support plane of the test bench is designed in the vertical axial direction of the mounting table, cooperates with the peripheral fixed support, and constructs a high-stability and high-precision test reference system, which takes into account mechanical stability, test authenticity and operation convenience, and is especially suitable for high-precision calibration and durability test scenarios.

[0022] In some embodiments, the sliding block has oppositely arranged first and second side surfaces, the clamping block is fixedly arranged on the first side surface, and the pressure sensor is fixedly arranged on the second side surface.

[0023] The clamping block is fixed on the first side surface of the sliding block and directly contacts the brake shoe, and the radial clamping force driven by the EPB motor is transmitted to the sliding block without attenuation; the pressure sensor is integrated on the second side surface of the sliding block, and the contact pressure borne by the clamping block is converted into a measurable signal of the sensor through the rigid structure of the sliding block, avoiding the force loss problem of traditional indirect measurement. The symmetrical layout of the clamping block and the pressure sensor makes the sliding block have no additional bending moment when stressed, ensuring that the pressure sensor only detects pure radial force and reducing data deviation.

[0024] In some embodiments, each clamping block is further connected with a distance measuring sensor.

[0025] The distance measuring sensor is used to dynamically detect the position of the clamping block, record the movement stroke of the brake shoe driven by the EPB motor, verify whether the design theoretical value is reached, and evaluate the response speed and motion stability of the EPB system through the displacement-time curve.

[0026] In some embodiments, the distance measuring sensor is a grating ruler sensor.

[0027] The clamping block is provided with a mounting groove, the grating ruler sensor is fixed in the mounting groove, and the detection end of the grating ruler sensor extends to the contact surface of the clamping block.

[0028] The integrated design of the grating ruler sensor and the clamping block realizes full-dimensional quantitative evaluation of the performance of the electronic parking brake through high-precision displacement monitoring and force-displacement collaborative analysis. The mounting groove fixing mode ensures data reliability while taking into account compactness, durability and maintenance convenience, improving the practicality of the parking test device.

[0029] In a possible implementation manner, the electronic parking module comprises:

[0030] a control unit;

[0031] an electronic parking power supply unit arranged on the test bench and electrically connected with the control unit and the tested piece;

[0032] a voltage sensor electrically connected with the electronic parking power supply unit; and

[0033] a current sensor electrically connected with the electronic parking power supply unit.

[0034] The electronic parking module precisely drives through electric control parameters and cooperatively feeds back through multiple sensors, not only meets the detection requirement of the pressure sensor on the clamping force, but also further realizes the correlation analysis of the electrical performance and mechanical performance of the EPB system, and fills the gap of the split of the electric control and mechanical data in the traditional test.

[0035] In a possible implementation manner, the drum brake electronic parking test device further comprises:

[0036] a hydraulic system fixedly arranged on the test bench and connected with the tested piece.

[0037] The introduction of the hydraulic system makes the parking test device upgrade from the single electronic parking function verification to the full braking system test platform, covers the driving, parking and composite braking scenes, improves the engineering applicability of the test, and provides a more comprehensive verification means for the safety and compliance of the drum brake. BRIEF DESCRIPTION OF DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0039] Figure 1 The structure diagram of the drum brake electronic parking test device provided by the embodiment of the present application Figure 1 ;

[0040] Figure 2 The structure diagram of the drum brake electronic parking test device provided by the embodiment of the present application Figure 2 ;

[0041] Figure 3 The structure diagram of the simulation drum structure of the drum brake electronic parking test device provided by the embodiment of the present application

[0042] Figure 4The utility model discloses a structure schematic diagram of electronic parking module of drum brake electronic parking test device.

[0043] In the drawing:

[0044] 1, test platform, 11, support plane, 12, installation platform,

[0045] 2, analog drum structure, 21, clamping block, 211, installation groove, 22, sliding block, 23, fixed support,

[0046] 3, pressure sensor,

[0047] 4, electronic parking module, 41, control unit, 411, host computer, 412, data collector, 42, electronic parking power supply unit, 43, voltage sensor, 44, current sensor,

[0048] 5, distance measuring sensor,

[0049] 6, hydraulic system,

[0050] 100, measured piece. DETAILED DESCRIPTION

[0051] In order to make the technical problem, technical scheme and beneficial effect of the utility model to be solved more clearly, the utility model is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the utility model and not to limit the utility model.

[0052] It should be noted that when an element is referred to as "provided on" another element, it can be directly on the other element or indirectly on the other element. It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the utility model.

[0053] The terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the utility model, the meaning of "several" is two or more than two, unless otherwise specifically limited.

[0054] The drum brake mainly consists of a brake drum, brake shoes, a brake backplate, a wheel cylinder (brake booster), a return spring and the like. The brake drum is a metal drum with an inner circular surface and is fixed to the wheel hub to rotate with the wheel. The brake shoes are in the shape of a fan and are generally two in number and are mounted on the brake backplate to swing around the fulcrum. The wheel cylinder is provided with a piston, and when brake fluid is pushed into the wheel cylinder, the piston pushes the brake shoes to open outward, so that the friction plate of the brake shoe is pressed against the inner circular surface of the brake drum to generate braking force. The return spring is used to restore the brake shoes to the original position after braking.

[0055] The drum brake can be braked by hydraulic pressure, electronic braking or hand brake. When the hydraulic brake, the brake pressure is transmitted to the booster assembly through the pipeline, the piston pushes the brake shoe to make it adhere to the brake drum, and the brake is realized. When the electronic parking brake, the driver presses the parking button, the ECU drives the electronic parking unit to clamp, so that the brake shoe adheres to the brake drum, and the parking is realized. When the hand brake, the brake shoe is driven to contact the brake drum by manually operating the pull rod or handle and the like, and the parking is realized.

[0056] The parking clamping force of the drum brake directly affects the parking effect. When the parking clamping force is large, the structure of the drum brake will be damaged, and when the parking clamping force is small, the flat or slope parking requirements cannot be met, causing the vehicle to slide down when parked, which seriously affects the parking safety. Therefore, it is necessary to use a test device to detect the parking clamping force of the drum brake.

[0057] However, the existing test device is only suitable for hand-pulled mechanical parking brake and cannot be adapted to electronic parking (EPB) drum brake because the driving mode (ECU control motor instead of mechanical cable) and the clamping force dynamic adjustment characteristics are completely different from the traditional system.

[0058] In order to solve the above problems and fill the technical blank of electronic parking brake test, please refer to Figures 1 to 4 , the drum brake electronic parking test device provided by the utility model will be described. The drum brake electronic parking test device comprises a test table 1, an analog drum structure 2 and an electronic parking module 4. The test table 1 has a mounting position for fixing the measured part 100. The analog drum structure 2 is arranged on the test table 1 and surrounds the radial periphery of the measured part 100 and contacts the brake shoe of the measured part 100. The analog drum structure 2 is connected with a pressure sensor 3. The electronic parking module 4 is electrically connected with the measured part 100 and is used for controlling the parking brake of the measured part 100.

[0059] It should be noted that the above-mentioned measured piece 100 refers to the measured drum brake. The simulation drum structure 2 is used to simulate the brake drum. In the specific detection, the electronic parking module 4 controls the measured piece 100 to perform the clamping action, so that the brake shoe is attached to the brake drum, and the parking is realized.

[0060] Specifically, the test bench 1 is provided with a standardized mounting position, which is rigidly connected with the shell (such as the brake bottom plate) of the measured piece 100 through a clamp or a bolt interface or other fastening structure, so as to ensure that the measured piece 100 is not displaced or vibrated during the test. The mounting position needs to support the quick installation of drum brakes of different specifications (such as large-size brakes for commercial vehicles or compact brakes for passenger vehicles), and flexible adaptation is realized through the support or modular interface at the adjustable mounting position.

[0061] The test bench 1 and the mounting position are used to ensure the accurate positioning of the measured piece 100. After the measured piece 100 is fixed, the contact position of the brake shoe and the simulation drum structure 2 can remain constant, so as to avoid measurement errors caused by installation deviation and ensure the reliability of the test data.

[0062] The simulation drum structure 2 replaces the real brake drum, and the inner diameter and surface material (such as steel or composite material) thereof are consistent with the actual installation conditions of the measured brake, and surround the outer edge of the brake shoe. The simulation drum structure 2 can be designed as a slightly elastic deformation structure (such as a split structure), so as to reflect the influence of the deformation of the real brake drum under the clamping force on the contact pressure.

[0063] The pressure sensor 3 is embedded in the inner wall of the simulation drum, or contacts the brake shoe through a distributed contact, or is arranged on the simulation drum structure 2. The pressure sensor 3 detects the normal pressure (i.e. the clamping force) applied by the brake shoe to the simulation drum structure 2 in real time, and the data is transmitted to the upper computer 411 synchronously.

[0064] Compared with the traditional rigid clamp directly measuring the thrust, the simulation drum structure 2 is closer to the stress state of the actual brake drum, and the measurement result more accurately reflects the parking performance after installation. The pressure sensor 3 feeds back the contact pressure in real time, so as to capture the clamping force building process (such as the force change curve of the motor-driven brake shoe expansion to stable clamping), and assist in analyzing the response time and stability.

[0065] In addition, the upper computer 411 can set a clamping force threshold (such as a maximum allowable pressure), which automatically triggers an alarm and stops the test when it is exceeded, so as to prevent the brake shoe or the simulation drum structure 2 from being damaged due to overload.

[0066] The electronic parking module 4 is connected to the ECU (Electronic Control Unit) of the brake under test via a wiring harness. It simulates control signals under actual vehicle operating conditions, triggering the electronic parking unit (EPB motor) to perform clamping or releasing actions. Preferably, the electronic parking module 4 supports multiple parking mode tests, including static parking (vehicle stationary), dynamic emergency braking (triggered while driving), and hill hold, with different trigger conditions set through programming.

[0067] The electronic parking brake module 4 directly interfaces with the ECU, solving the problem that traditional testing devices cannot simulate electronic signal drive and filling the testing gap for electronic parking brakes. Preferably, the electronic parking brake module 4 can also reproduce complex scenarios (such as changes in motor starting torque under low temperature conditions and durability tests of frequent parking / release) to verify the reliability of the electronic parking brake system under different conditions.

[0068] The drum brake electronic parking brake testing device provided by this utility model, compared with the prior art, provides a stable mounting base for the simulated drum and the electronic parking module 4 on the test bench 1, ensuring that the spatial relationship of the three is consistent with the actual vehicle, eliminating external interference, and ensuring the consistency of the testing environment. The simulated drum structure 2 converts the clamping action driven by the electronic parking module 4 into a quantifiable pressure signal, and together with the test bench 1, constrains the movement of the test component 100, realizing a closed-loop test link of "electronic control mechanical action - data feedback". The electronic parking module 4 drives the test component 100 to perform the parking action, and at the same time, it links with the pressure data of the simulated drum to verify the accuracy of the ECU control logic.

[0069] This invention integrates an electronic parking brake module 4, which is directly electrically connected to the electronic control unit of the test component 100, to simulate the electronic parking brake trigger signal of a real vehicle. It also directly detects the contact pressure between the brake pads and the simulated drum through a pressure sensor 3, thus solving the problem of input and execution of electronic control signals and enabling the testing device to accurately reproduce the working conditions of electronic parking brake.

[0070] In some embodiments, the simulated drum structure 2 described above can be adopted as follows: Figure 1 , Figure 2 and Figure 3 The structure shown is described in the following document. Figure 1 , Figure 2 and Figure 3 The simulated drum structure 2 includes at least two clamping blocks 21, which are spaced apart on the radial periphery of the test piece 100 and each is in contact with the brake shoe of the test piece 100; each clamping block 21 is slidably connected to the test bench 1.

[0071] The simulation drum structure 2 comprises at least two clamping blocks 21, that is, the simulation drum structure 2 is split, and each clamping block 21 can be designed to have slight elastic deformation to reflect the influence of the deformation of the real brake drum under the clamping force on the contact pressure.

[0072] Each clamping block 21 is respectively connected with the test bench 1 in sliding mode, specifically, can be connected with the test bench 1 through sliding guide rails (such as linear bearings or sliding blocks), allowing it to move freely in the radial direction to adapt to the detection needs of drum brakes of different diameters. Moreover, the initial position of the clamping block 21 can also be actively adjusted to simulate the brake drum clearance under different wear states. In addition, the sliding connection can also ensure that the clamping block 21 is always in close contact with the brake shoe, avoiding the local pressure concentration caused by installation errors of traditional rigid clamps, so that the data is closer to the actual stress state of the brake drum.

[0073] Specifically, each clamping block 21 is independently connected with a pressure sensor 3 to monitor the clamping force distribution of the corresponding brake shoe in real time. Compared with a single pressure sensor 3, the multi-clamping block 21 design can capture the force difference at different positions of the brake shoe (such as uneven pressure at both ends and the middle of the brake shoe), and evaluate the risk of uneven wear of the drum brake assembly.

[0074] The design of at least two clamping blocks 21 realizes more accurate, flexible and safe electronic parking brake testing through sliding connection + multi-point pressure detection, which is especially suitable for drum brake research and development and quality control with strict requirements on clamping force distribution.

[0075] In some embodiments, the above-mentioned simulation drum structure 2 can also adopt the structures shown in Figure 1 、 Figure 2 and Figure 3 , see Figure 1 、 Figure 2 and Figure 3 , the simulation drum structure 2 further comprises at least two sliding blocks 22. The at least two sliding blocks 22 are connected one by one with the at least two clamping blocks 21; each sliding block 22 is connected with the test bench 1 in sliding mode. The sliding block 22 is used to drive the clamping block 21 to move linearly on the test bench 1.

[0076] The sliding block 22 is an intermediate transmission component connecting the clamping block 21 and the test bench 1, ensuring that the clamping block 21 moves and accurately fits the brake shoe. Specifically, the sliding block 22 is connected with the clamping block 21, but is flexibly coupled with the test bench 1 through a sliding power mechanism to reduce the interference of external vibration or installation error on the pressure sensor 3.

[0077] Preferably, the sliding block 22 and the clamping block 21 are detachably connected, so that the clamping block 21 can be replaced when it wears or the wear exceeds a preset value. In addition, the corresponding clamping block 21 can be replaced according to the different models and sizes of the test piece 100 to improve the versatility of the drum brake electronic parking test device.

[0078] In practical use, before testing, the parking test device drives the sliding block 22 to move the clamping block 21 inward / outward, setting the initial gap with the brake pads. When the EPB motor drives the brake pads to expand, the brake pads push the clamping block 21, which slides through the sliding block 22, following the displacement of the brake pads in real time. At the same time, the pressure sensor 3 records the dynamic clamping force.

[0079] By precisely controlling the position of the clamping block 21 through the sliding block 22, different wear conditions can be simulated (such as the gap between the shoe and the drum ranging from 0.1mm to 1.5mm), verifying the adaptive capability of the electronic parking brake unit. Furthermore, in conjunction with the programmed control of the test bench 1, the sliding block 22 can perform periodic reciprocating motion to simulate the durability test of frequent parking brake release.

[0080] In addition, each clamping block 21 is connected to a corresponding sliding block 22. Multiple sliding blocks 22 can move independently. Even if one side of the brake shoe is stuck, the other sliding blocks 22 can still slide normally, thus preventing the system from locking up.

[0081] In some embodiments, the above-described drum brake electronic parking test device may also employ, for example... Figure 1 , Figure 2 and Figure 3 The structure shown is described in the following document. Figure 1 , Figure 2 and Figure 3 The test bench 1 is provided with a fixed bracket 23, which is located radially around the installation position; at least two sliding blocks 22 are slidably disposed on the fixed bracket 23. The fixed bracket 23 is the sliding base for the sliding blocks 22 and the clamping blocks 21.

[0082] The fixed bracket 23 is the core structural component in the test bench 1 that supports the movement of the sliding block 22 and the clamping block 21. A linear guide rail is integrated on the fixed bracket 23, and the sliding block 22 is slidably connected to the linear guide rail, thereby ensuring that the sliding block 22 can only move radially in a straight line, preventing the clamping block 21 from tilting or twisting, and ensuring that the pressure detection direction is consistent with the force direction of the brake shoe being tested. In addition, as a sliding base, the fixed bracket 23 can withstand the reaction force of the brake shoe when the EPB motor clamps with high torque or releases quickly, preventing deformation of the test bench 1 from affecting measurement accuracy.

[0083] The fixed support 23 is distributed around the mounting position. It should be noted that the linear guide rails on the fixed support 23 correspond to at least two groups of sliding blocks 22 respectively, so as to ensure that the at least two groups of sliding blocks 22 slide in respective sliding directions. In addition, the fixed support 23 is also provided with a power mechanism (such as a linear motor). Preferably, each sliding block 22 is correspondingly connected to a group of power mechanisms, and the power mechanism is used to drive the corresponding sliding block 22 to slide.

[0084] Preferably, as shown in Figure 1 , Figure 2 and Figure 3 , the embodiment is provided with two groups of sliding blocks 22 and two groups of clamping blocks 21. The two groups of clamping blocks 21 are symmetrically arranged, and the two groups of sliding blocks 22 are also symmetrically arranged. The sliding block 22 and the corresponding clamping block 21 slide in the horizontal direction.

[0085] The clamping block 21 and the sliding block 22 slide in the horizontal direction, which significantly improves the balance of the test and the reliability of the data. By synchronously contacting the two sides of the brake shoe through the two groups of symmetrically distributed clamping blocks 21, the symmetry of the force when the brake shoe expands can be accurately detected, and the error caused by single-point measurement can be avoided. The horizontal sliding design of the sliding block 22 not only ensures that the clamping block 21 always moves in the radial direction, but also simplifies the structure of the fixed support 23, facilitating maintenance and calibration.

[0086] This structure is especially suitable for verifying the bidirectional balanced clamping capability of the electronic parking brake unit (EPB). If an asymmetric force value is found during the test, the problem (such as single-sided motor transmission jamming or brake shoe return spring failure) can be quickly located, thereby improving the safety and consistency of the brake.

[0087] In some embodiments, the test bench 1 described above can also adopt the structure as shown in Figure 1 , as shown in Figure 1 , the test bench 1 has a support plane 11, the support plane 11 is provided with a mounting table 12, the mounting position is arranged on the mounting table 12, and the axial direction of the mounting position is perpendicular to the support plane 11; the fixed support 23 is fixedly arranged on the support plane 11 and located at the periphery of the mounting table 12.

[0088] The support plane 11 provides a rigid foundation for the test bench 1, which is used to support the fixed support 23 and the mounting table 12, so as to ensure that the axial direction of the drum brake under test is perpendicular to the direction of gravity, and eliminate the clamping force measurement deviation caused by inclination;

[0089] The axial direction of the mounting position is arranged perpendicular to the support plane 11, so that the clamping direction of the brake assembly is consistent with the actual vehicle-mounted state, simulating the real stress working condition. The fixed support 23 is arranged around the periphery of the mounting table 12, which not only provides support for the sliding block 22-clamping block 21 system, but also offsets the radial reaction force in the test through the symmetric frame structure, so as to reduce the measurement error of the pressure sensor 3.

[0090] The support plane 11 of the test table 1 and the vertical axial design of the mounting table 12, in cooperation with the peripheral fixed support 23, construct a high-stability and high-precision test reference system, which takes into account mechanical stability, test authenticity and operation convenience, and is especially suitable for high-precision calibration and durability test scenarios.

[0091] In some embodiments, the clamping block 21 described above can adopt a structure as shown in Figure 3 , referring to Figure 3 , the sliding block 22 has a first side and a second side arranged oppositely, the clamping block 21 is fixedly arranged on the first side, and the pressure sensor 3 is fixedly arranged on the second side.

[0092] The clamping block 21 is fixed on the first side of the sliding block 22 and directly contacts the brake shoe, so that the radial clamping force driven by the EPB motor is transmitted to the sliding block 22 without attenuation; the pressure sensor 3 is integrated on the second side of the sliding block 22, and the contact pressure borne by the clamping block 21 is converted into a measurable signal of the sensor through the rigid structure of the sliding block 22, avoiding the problem of force loss in traditional indirect measurement. The symmetrical layout of the clamping block 21 and the pressure sensor 3 makes the sliding block 22 have no additional bending moment when stressed, ensuring that the pressure sensor 3 only detects pure radial force and reducing data deviation.

[0093] Specifically, a clamping groove can be arranged on the first side of the sliding block 22, and the clamping block 21 is partially clamped in the clamping groove to support quick disassembly and replacement of the clamping block, and adapt to testing of brakes with different friction plate profiles. The pressure sensor 3 is independently packaged on the second side and has a standardized electrical interface with the sliding block 22, so that it can be replaced individually when damaged, reducing maintenance costs.

[0094] In some embodiments, the drum brake electronic parking test device described above can also adopt a structure as shown in Figure 1 , Figure 2 and Figure 3 , referring to Figure 1 , Figure 2 and Figure 3 , each clamping block 21 is further connected with a distance measuring sensor 5.

[0095] The distance measuring sensor 5 is used for dynamically detecting the position of the clamping block 21, recording the movement stroke of the brake shoe under the driving of the EPB motor, verifying whether the designed theoretical value is reached, and evaluating the response speed and motion stability of the EPB system through the displacement-time curve. Before testing, the distance measuring sensor 5 can measure the initial gap between the clamping block 21 and the simulation drum, which is used to simulate the working condition of the brake drum in different wear states. In the cycle test, the distance measuring sensor 5 tracks the wear amount of the friction material of the brake shoe through displacement data, so as to predict the service life.

[0096] Specifically, the distance measuring sensor 5 is a grating ruler sensor; the clamping block 21 is provided with a mounting groove 211, the grating ruler sensor is fixed in the mounting groove 211, and a detection end of the grating ruler sensor extends to a contact surface of the clamping block 21.

[0097] The mounting groove 211 of the clamping block 21 embeds the grating ruler sensor in the inside, avoids interference of an external sensor with movement of the clamping block 21 or occupation of space of the test bench 1. Moreover, the mounting groove 211 can form protection for the grating ruler sensor, preventing debris or oil stains in testing from directly polluting grating bars of the grating ruler sensor.

[0098] The detection end of the grating ruler sensor extends to the contact surface of the clamping block 21, so as to eliminate mis-touch of a transmission chain, and detection data more directly reflects real working conditions.

[0099] Specifically, the mounting groove 211 includes a clamping portion and a containing portion connected in sequence, the grating ruler sensor is partially located in the containing portion and partially clamped in the clamping portion, the grating ruler sensor is detachably connected with the clamping block 21, and the grating ruler sensor can be replaced without disassembling the entire clamping block 21 when damaged.

[0100] The integrated design of the grating ruler sensor and the clamping block 21 realizes full-dimensional quantitative evaluation of performance of an electronic parking brake through high-precision displacement monitoring + force-displacement collaborative analysis. The mounting groove 211 fixing mode guarantees data reliability, takes into account compactness, durability and maintenance convenience, and improves practicality of the parking test device.

[0101] In some embodiments, the electronic parking module 4 described above can adopt a structure as shown in Figure 4 , referring to Figure 4 , the electronic parking module 4 includes a control unit 41, an electronic parking power supply unit 42, a voltage sensor 43 and a current sensor 44. The electronic parking power supply unit 42 is arranged on the test bench 1 and is electrically connected with the control unit 41 and the measured piece 100; the voltage sensor 43 is electrically connected with the electronic parking power supply unit 42; and the current sensor 44 is electrically connected with the electronic parking power supply unit 42.

[0102] Specifically, the control unit 41 includes a host computer 411 and a data collector 412. Before the test, the host computer 411 is set with test voltage, drum brake electronic parking cut-off current, drum brake electronic parking holding time, drum brake electronic parking back-off time and other key parameters; after starting the test, the electronic parking power supply unit 42 is started according to the parameters set by the host computer 411, and the measured product is powered, and the real-time current value of the current sensor 44, the real-time voltage value of the voltage sensor 43, and the real-time clamping force value of the pressure sensor 3 are collected by the data acquisition system. When the real-time current value of the current sensor 44 reaches the cut-off current set by the host computer 411, the host computer 411 controls the electronic parking power supply unit 42 to stop power supply; the data collector 412 collects the stable clamping force value after two seconds of stopping power supply as the measured clamping force value, and records the no-load current value in the clamping stage, and the clamping stage test is completed. After the clamping stage test is completed, the electronic parking power supply unit 42 is started again, and a negative voltage is applied to the measured product through the reversing relay to release the measured product, and the test is completed.

[0103] The electronic parking module 4 sets the test voltage, cut-off current, holding time and other key parameters through the host computer 411, which can flexibly adapt to the EPB performance requirements of different models of drum brakes, and realize the standardized test process. The data collector 412 collects current, voltage and clamping force data in real time, and verifies whether the torque output of the EPB motor under the set voltage meets the standard.

[0104] When the real-time current value of the current sensor 44 reaches the cut-off current set by the host computer 411, the host computer 411 controls the electronic parking power supply unit 42 to stop power supply, which not only simulates the overcurrent protection logic of the vehicle ECU, but also prevents the measured part 100 from being damaged during the test; record the clamping force after stopping power supply for 2 seconds, which can eliminate the interference of motor inertia and ensure that the data reflects the true mechanical self-locking force.

[0105] The electronic parking module 4 precisely drives through electric control parameters + multi-sensor cooperative feedback, not only meets the detection requirements of the pressure sensor 3 on the clamping force, but also further realizes the correlation analysis of the electrical performance and mechanical performance of the EPB system, and fills the gap between the traditional test and the mechanical data.

[0106] In some embodiments, the above-mentioned drum brake electronic parking test device can also adopt the structure as shown in Figure 1 , referring to Figure 1 , the drum brake electronic parking test device further comprises a hydraulic system 6; the hydraulic system 6 is fixedly arranged on the test bench 1 and connected with the measured part 100.

[0107] The hydraulic system 6 is used for carrying out service brake on the measured piece 100, is connected with the brake wheel cylinder of the measured piece 100 through pipeline, simulates the hydraulic brake pipeline of real vehicle. Specifically, during testing, the hydraulic system 6 supplies oil to the brake wheel cylinder according to the preset pressure curve, pushes the piston to make the brake shoe press the simulation drum structure 2, simulates the hydraulic braking process when the vehicle is decelerated or parked. When parking brake, hydraulic brake is triggered first to make brake shoe contact with simulation drum, then electronic parking module 4 is started to clamp, and the intervention performance of EPB under the residual pressure of hydraulic pressure is verified. After testing, the hydraulic system 6 releases the oil pressure quickly through the pressure relief valve, so that the brake shoe resets, and the negative voltage release of the electronic parking module 4 is matched, so that the brake cycle is completed.

[0108] The hydraulic system 6 can simulate the brake force demand corresponding to different deceleration, and verify the dynamic response of drum brake under hydraulic drive. The introduction of the hydraulic system 6 upgrades the parking test device from single electronic parking function verification to full brake system test platform, covers service brake, parking and composite brake scenes, improves the engineering applicability of the test, and provides a more comprehensive verification method for the safety and compliance of drum brake.

[0109] The above only describes the preferred embodiments of the present application, and is not used to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A drum brake electronic parking brake testing device, characterized in that, include: The test stand (1) has a mounting position for fixing the test piece (100). A simulated drum structure (2) is disposed on the test bench (1), surrounding the radial periphery of the test piece (100), and in contact with the brake pads of the test piece (100); the simulated drum structure (2) is connected to a pressure sensor (3), which is used to detect the pressure applied by the brake pads to the simulated drum structure (2); and The electronic parking module (4) is electrically connected to the test piece (100) and is used to control the parking brake of the test piece (100).

2. The electronic parking brake testing device for drum brakes as described in claim 1, characterized in that, The simulated drum structure (2) includes: At least two clamping blocks (21) are spaced apart on the radial periphery of the test piece (100) and each is in contact with the brake shoe of the test piece (100); each clamping block (21) is slidably connected to the test bench (1).

3. The electronic parking brake testing device for drum brakes as described in claim 2, characterized in that, The simulated drum structure (2) also includes: At least two sliding blocks (22) are connected one-to-one with at least two clamping blocks (21); the clamping blocks (21) are slidably connected to the test bench (1) through the sliding blocks (22).

4. The electronic parking brake testing device for drum brakes as described in claim 3, characterized in that, The test bench (1) is provided with a fixed bracket (23), which is located on the radial periphery of the mounting position; at least two sliding blocks (22) are slidably disposed on the fixed bracket (23).

5. The electronic parking brake testing device for drum brakes as described in claim 4, characterized in that, The test bench (1) has a support plane (11), and a mounting platform (12) is provided on the support plane (11). The mounting position is located on the mounting platform (12), and the axis of the mounting position is perpendicular to the support plane (11). The fixed bracket (23) is fixedly installed on the support plane (11) and located on the periphery of the mounting platform (12).

6. The electronic parking brake testing device for drum brakes as described in claim 3, characterized in that, The sliding block (22) has a first side and a second side that are arranged opposite to each other. The clamping block (21) is fixedly arranged on the first side, and the pressure sensor (3) is fixedly arranged on the second side.

7. The electronic parking brake testing device for drum brakes as described in claim 2, characterized in that, Each of the clamping blocks (21) is also connected to a ranging sensor (5).

8. The electronic parking brake testing device for drum brakes as described in claim 7, characterized in that, The ranging sensor (5) is a grating ruler sensor; The clamping block (21) is provided with a mounting groove (211), the grating ruler sensor is fixed in the mounting groove (211), and the detection end of the grating ruler sensor extends to the contact surface of the clamping block (21).

9. The electronic parking brake testing device for drum brakes as described in claim 1, characterized in that, The electronic parking module (4) includes: Control unit (41); An electronic parking power supply unit (42) is installed on the test bench (1) and is electrically connected to the control unit (41) and the test piece (100); Voltage sensor (43), electrically connected to the electronic parking power supply unit (42); and The current sensor (44) is electrically connected to the electronic parking power supply unit (42).

10. The electronic parking brake testing device for drum brakes as described in claim 1, characterized in that, The drum brake electronic parking brake testing device also includes: The hydraulic system (6) is fixedly installed on the test bench (1) and connected to the test piece (100).

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